Insulating baffle for refrigerator evaporators



NOV. 16, 1954 RQSEBR'QQK 2,694,295

INSULATING BAFFLE FOR REFRIGERATOR EVAPORATORS Filed Jan. 17, 1951INVENTOR. HOME/2 E. Easaaeoox Mag/WM 2,694,295 Patented Nov. 16, 1954free ENULATING BAFFLE FGR REFRIGERATOR EVAPORATORS Homer E. Rosebrook,Greenville, Mich, assignor t Gibson Refrigerator Company, Greenville,Mich., a corporation of Michigan Application January 17, 1951, SerialNo. 206,337 3 Claims. (Cl. 6210.3)

This invention relates to refrigerators, particularly those of theconvection type.

Modern household refrigerators are usually cooled by means of anevaporator located adjacent the top thereof and maintained at atemperature considerably below freezing. Also, such evaporators areordinarily provided with means for regulating the evaporator temperaturewithin certain limits, so that on occasion the evaporator temperaturemay be lowered for quicker freezing water or foodstuffs within theevaporator.

The temperature maintained within the refrigerator storage compartmentis dependent primarily upon the temperature of the evaporator, thereforewhen the evaporator temperature is lowered, the food storagecompartment, particularly that portion close to the evaporator and belowit, may become too cold and freeze articles not intended to be frozen.

The present invention avoids to a large extent the aforementioneddisadvantage by providing a variable insulating battle below theevaporator. The insulating effect is automatically variable to a degree,dependent upon the evaporator temperature. In general the inventioncomprises a baffle plate having a lower coefficient of heat transmissionthan the material composing the evaporator, located close enough to theevaporator to produce a sub-freezing temperature throughout the bafileplate. Thus, frost builds up on or melts off the baflle, depending uponthe evaporator temperature, and as frost is an insulator, the insulatingeffect of the baflle varies.

In the drawings accompanying this application:

Figure 1 is a fragmentary front View of a refrigerator, with the doorremoved, showing the invention; and

Figure 2 is a fragmentary cross-sectional view taken on substantiallythe line 22 of Figure 1.

g The invention is shown as embodied in a household refrigerator cabinetit) of conventional construction. The refrigerator cabinet has a foodstorage compartment 11 therein, normally closed by a door, not shown.

In the upper part of the storage compartment is an evaporator 12 whichextends substantially from side to side, and from front to rear of thecompartment 11. The evaporator is preferably formed from metal having ahigh heat conductivity, such as aluminum or copper.

At each side of the evaporator are brackets 13 which support aninsulating bafile plate 14 below the evaporator. The bafile plate 14 ispreferably of glass or other material which has a lower coeflicient ofheat transmission than the material of the evaporator, but still willpass heat rather readily. The bafile plate 14 is of substantially thesame horizontal extent as the evaporator and is located very close tothe evaporator. For best results the lower surface of the baffle plateshould be within one inch of the evaporator. The battle plate 14inclines slightly downwardly and rearwardly. The baffle plate is mountedon the brackets 13 so that it may be completely removed in hot summerweather, or for any other reason if the user so desires.

Attached to the rear wall of the cabinet is an auxiliary baffle 15 whichinclines downwardly and forwardly beneath the rear edge of the baffleplate 14 and in close proximity thereto. The baflle 15 cooperates withthe bafile plate 14 in restricting the flow of air within therefrigerator and deflects moisture running off of the inclined baffleplate 14 onto a. drip pan 16 therebelow. The drip pan 16 is acombination storage shelf and drip pan supported below the baffle plate14 by suitable supporting brackets 17. The shelf 16 is preferablyimperforate, except for a small drain hole 18.

The shelf 16 is nearly as large as the cross-section of the compartment11. Consequently it too acts as a baffle to restrict the circulation ofair within the compartment 11. Thus the space between the shelf 16 andbaflle 14 is colder than the rest of the compartment below it, and maygo below freezing if the evaporator temperature is set low enough.However, when the evaporator temperature is lowered the moisture in theair within the compartment condenses out and freezes on the baffle plate14 rather rapidly, thus building up an insulating layer which reducesthe transfer of heat to the evaporator and maintains a more uniform andhigher temperature in the food storage compartment 11 than wouldotherwise be the case. When the temperature of the evaporator rises,some of the accumulated deposit of frost melts and drips from the baffleplate 14, reducing the insulating effect of the bafiie.

From the foregoing it will be seen that the present invention provides anovel means of maintaining more uniform conditions in a refrigerator,regardless of changes in evaporator temperature, than would ordinarilybe the case.

The scope of the invention is indicated in the appended claims.

1. A refrigerator cabinet having a food storage compartment therein, anevaporator in said compartment, a main baffle plate below saidevaporator and spaced closely enough to said evaporator to substantiallyprevent movement of air therebetween, said main baffle plate beingformed of material having a substantially lower coefiicient of heattransfer than the material composing the evaporator and being ofsubstantially the same horizontal extent as the evaporator, said mainbaffle plate being inclined downwardly toward a wall of saidcompartment, and a drip pan of substantially the same horizontal extentas the main baffle plate and spaced below said main baffie platesufficiently to permit free flow of air between said main bafile plateand said drip pan.

2. A refrigerator cabinet having a food storage compartment therein, anevaporator in said compartment, a main baffle plate below saidevaporator in closely spaced relation thereto, said main baffle platebeing formed of material having a substantially lower coefiicient ofheat transfer than the material composing the evaporator and being ofsubstantially the same horizontal extent as the evaporator, said mainbaffle plate being inclined downwardly toward a wall of saidcompartment, and a drip pan of substantially the same horizontal extentas the main boffie plate and spaced below the latter sufficiently topermit free flow of air between said main baffie plate and said drippan, and an auxiliary baffle on said wall extending under the lower edgeof said main baffle plate and over the corresponding edge of said drippan.

3. A refrigerator cabinet having a food storage com partrnent therein,an evaporator in said compartment, the horizontal extent of saidevaporator being substantially the same as that of the compartment, amain bafile plate below said evaporator, the lower surface of said mainbaffle plate bein spaced not over one inch from said evaporator wherebyto substantially prevent movement of air through the passages defined bythe bottom of the evaporator and the main baffle plate, said main baffieplate being formed of material having a substantially lower coefficientof heat transfer than the material composing the evaporator and being ofsubstantially the same horizontal extent as the evaporator, and a drippan of substantially the same horizontal extent as the main baffle plateand spaced below said main baffle plate sufiiciently to permit free flowof air between said main bafi le plate nd said drip pan.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,736,884 Mason Nov. 26, 1929 2,072,567 Potter Mar. 2, 19372,282,342 Preble May 12, 1942 2,292,032 Atchison Aug. 4, 1942 2,509,613Philipp May 30, 1950 2,511,126 Philipp June 13, 1950 2,563,975 TobeyAug. 14, 1951

